Use of domain knowledge, product models and geometric algorithms for generation of construction zones

Abstract: We present a layered approach for automated generation of construction zones from 3D CAD models for construction planning and scheduling. The existence of 3D models and product models provides an opportunity for planners and schedulers to consider zoning alternatives and represent and visualize production information in detail. Construction zones are spaces, or groups of spaces, which serve as units of work in the construction planning process. Failure to define construction zones properly may increase overall project duration and impact workflow adversely. Today, zone definitions are generally ad-hoc. Formal definitions and mechanisms to generate construction zone information are not available in commercially available software.We have defined a three-layer computational framework in a prototype construction management software tool to generate detailed information about construction zones. The framework separates the construction-based information from the product model representation and geometric information. Each layer is extensible and testable without the other layers. The highest layer (Layer3) contains domain knowledge about zones, i.e., types of zones and factors or constraints affecting construction zone definition. For example, a shape factor takes into account the changes in production rates due to local variations of geometry. The shape factor also allows the representation of an idle crew because of a nearby activity, missing support or unavailability of materials. Layer 2 manages the changes in the product and process models that are necessary to generate zones. Additionally, it uses zoning knowledge to maintain consistent schedules at multiple levels of detail. Layer 1 is the geometric level that contains the geometric algorithms to create the subdivisions and aggregations using the geometric shape representation of the building components. Instead of considering a fixed geometric representation for a component, we provide a flexible triangular mesh shape representation, breaking-up or aggregating component geometry as necessary.
With the results of this research, professionals will be able to simulate and visualize construction processes more accurately and link design and construction data more tightly to explore design-build scenarios rapidly and communicate them effectively.

Permission to reproduce these documents have been graciously provided by CSIR Building and Construction Technology. The assistance of the editors, Mr. Gustav Coetzee and Mr. Frances Boshoff, is gratefully appreciated.